<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02_变量与常量</title>
</head>
<body>
<div id="aaa">
  这是aaa
</div>
<script>
  // const a = 1;
var a = 1;
console.log(a);
var b = "你好,我是b";
console.log(b);
var b = '你好,b又来了';
console.log(b);
let x = '123';
console.log(x);
const y = 'y';
console.log(y);
var aaa = 'aaa';
console.log(aaa);
</script>
</body>
</html>